How Birds Perceive and use Compass Information From the Geomagnetic Field

Wolfgang Wiltschko and Roswitha Wiltschko

Abstract:	Magnetic compass orientation has been demonstrated in more than twenty bird species from different orders. The functional characteristics of the avian magnetic compass have been analyzed in few species only, but the existing evidence suggests a uniform mechanism among birds. The Radical Pair model describes a possible physical principle by which birds could detect magnetic directions, proposing direction-dependent chemical reactions in specialized photopigments in the eyes. This model is supported by experimental evidence; three predictions derived from it were found to be true: magnetoreception proved light-dependent; the underlying radical pair processes have been demonstrated, and magnetoreception was found to take place in the right eye. As magnetosensitive photopigments forming the radical pairs, cryptochromes have been suggested. Cryptochromes have been found in the retina of birds, and their sensitivity to changes in the ambient magnetic field has been demonstrated in plants, but direct evidence that they are involved in magnetoreception in birds is still lacking.
Published in:	Proceedings of the 63rd Annual Meeting of The Institute of Navigation (2007) April 23 - 25, 2007 Royal Sonesta Hotel Cambridge, MA
Pages:	25 - 31
Cite this article:	Wiltschko, Wolfgang, Wiltschko, Roswitha, "How Birds Perceive and use Compass Information From the Geomagnetic Field," Proceedings of the 63rd Annual Meeting of The Institute of Navigation (2007), Cambridge, MA, April 2007, pp. 25-31.
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